The ion mobility spectrometer is an instrument used for identification and analysis of chemical species, especially trace amounts of substances dispersed in a vapor phase such as the atmosphere or ambient of a reactor or analysis chamber. The ion mobility spectrometer emerged from developments in the late 1960's and early 1970's, and is now a well-established technology for defense and civilian applications. The technology continues to evolve as its use widens from specialized military equipment and laboratory instrumentation to serve more varied applications including those related to environmental monitoring, law enforcement, process control, and industrial hygiene and safety. In particular, ion mobility spectrometers are being used more frequently in trace analysis of explosives, narcotics, and biochemical warfare agents. Ion mobility spectrometers have gained broad acceptance in niche markets due to their relatively low cost, simple operation, and reliability. Moreover, ion mobility spectrometers are well-suited for miniaturization, portable deployment, and high-volume mass production. Even wider utilization of ion mobility spectrometers is expected with further reductions in their size, cost, and complexity. The present invention addresses these aspects of design and construction, leading to broad based improvements in ion mobility spectrometer technology.